How long do you have in between grandma leaving and you leaving on your trip? If it's a week or two, I think you definitely have enough time to get started. He may regress a bit on the trip, but usually it comes back quicker once you've already put in the tough work of training. That being said, if you don't think you will be committed fully because of the trip and/or his current teething, then it might be worth it to wait. There's not much of a difference in sleep training an 11/12/13mo old, as I'm assuming he's already pulling up to standing in the crib and moving around in it.
If you're going to wait, I would definitely do it starting in his room and put up a bed for you to sleep in the first few nights as well. He is used to sleeping in the same bedroom as you and you will want to reestablish trust with him after CIO, so this will be the best way to do that.
What do you believe would give the best results in getting him to calm himself and sleep on his own?
I'm not exactly sure what you're asking here and if I've answered it above, but I would say to be really consistent in how you sleep train, reassuring him but not giving help when it's not needed. Use your voice and encourage him to do what he is capable of doing (lying down and going to sleep), even though he hasn't done it before. At this age, he is really starting to understand what you say, so explain to him that he will be going to sleep in his crib, you will stay with him, but he needs to lie down and go to sleep, etc etc. It may not seem like he's ever going to calm down the first time you try, but I promise he eventually will and will learn how to do it on his own.
Hope that helps! Please let us know what other questions you have.
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